TD n. 607 2013
João Manoel Pinho de Mello, Daniel Ricardo de Castro Cerqueira.
We report two results. First, we evaluate the impact of a nationwide anti-firearm legislation passed
by the Brazilian Congress in December 2003 (Estatuto do Desarmamento, henceforth ED). Our identification
strategy hinges on the hypothesis that the law had stronger impact in places where gun prevalence was
higher in the baseline. We find evidence that homicides (reduced form) and firearms prevalence
(mechanism or first-stage) dropped faster in places with higher gun prevalence after the 2003. Using our
preferred estimates, the ED saved between 2,000 and 2,750 lives from 2004 through 2007 in cities with
more than 50,000 inhabitants in the state of São Paulo. Second, assuming the ED causes homicide only
through its impact on firearms prevalence, we recover a causal estimate of the impact of firearms on
homicides. One standard deviation in the prevalence of firearms reduces homicides by quarter of a
standard deviation. We find no impact of both ED and firearms on property crime in general or on
robberies.